Barn or gutter cleaners are well known in the art. A barn cleaner of the type to which the present invention applies includes a gutter system that runs through the barn area as, for example, along animal stalls. A scraper chain conveyor is received in and runs through the gutter system. Animal refuse, straw and other debris are scraped and washed from the stalls and deposited conveniently into the adjacent gutter. The scraper chain conveyor is activated periodically and the flights or paddles of the scraper chain convey the refuse and debris through the gutter system and out of the barn up along an inclined chute for delivery into a holding bin, manure pit, compost pile, or the like.
Barn cleaner chains have previously included coupled hook links. Each hook link includes a hook portion and a link portion. The hook portion of one hook link is extended through the longitudinal slot of the link portion of an adjacent hook link. The closed end of the hook is then brought into engagement with the link portion forming the end of the slot to complete the assembly. Multiple hook links combined in this fashion form the chain.
One problem with chains formed from hook links is a tendency to uncouple, particularly during slackening and snaking on the return run down the inclined chute back to the barn. Often, before such an uncoupling is discovered, an entire chain is disassembled and has even unloaded one or several hook links and paddle assemblies from the conveyor into the spreader or manure pit. It should be appreciated that the hook links and paddle assemblies are difficult, if not impossible to retrieve under these circumstances. Additionally, it is very time consuming to have to reconnect each of the hook links and again install the chain in the gutter for operation.
Several attempts have been made in the art to address and solve this uncoupling problem. In U.S. Pat. No. 2,853,887 to Johnson, each hook link is provided with a removable lock pin that is driven into a seated position between the end of the hook and the hook link body to close the throat of the hook and retain the hook links in the coupled state. When properly seated, the pin is effective in theory to prevent the uncoupling of adjacent hook links. It, however, should be appreciated that hook links and paddle assemblies constructed in this manner are, due to being subject to rough treatment during service, prone to being accidentally uncoupled due to the lock pin being knocked loose and lost. Further, removal of the lock pin each time a hook link is to be disconnected can be particularly tedious and time consuming. On the other hand, under some severe service conditions the lock pins can become rusted or frozen in position and made difficult, and sometimes impossible, to remove. For these and other reasons, hook links with separate locking pins have achieved only limited success in the market place.
Another approach to solving the uncoupling problem is found in U.S. Pat. No. 2,785,578 to Nold. Nold discloses a conveyor chain formed from a series of alternating substantially oval links and double hook links. Each oval link includes a portion of reduced cross-sectional area that slips through the throat of the hook for connection to the double hook link and formation of the chain. By eliminating the separate lock pin seated in the throat of the hook the Nold chain does not suffer the same disadvantages but is simply more prone to being accidentally uncoupled.
Specifically, the Nold chain is prone to uncoupling during incidental slackening of the chain that often takes place during conveyor operation, especially on the return run. Since each oval link receives a hook of a double hook link at each end, the reduced cross-sectional portion of the link (that allows coupling and uncoupling) is positioned adjacent one of the hooks. As the chain slackens, the hook, adjacent the reduced cross-sectional portion, can easily slide along the link until the throat engages the reduced portion. At this point simple movement of the hook in a straight line, such as may be caused by gravity or the taking up of the slack on the chain, causes the hook of the double hook link to uncouple from the oval link.
In addition to the shortcomings of the hook link design, the prior art barn cleaners have not been designed so as to allow replacement of a paddle and/or wear shoe independently of the hook link. Furthermore, for still further economy with respect to replacement parts, it would be desirable to have the paddle and wear shoe interchangeable for clockwise (CW) and counterclockwise (CCW) conveyor operation.
From the above it is clear that a need exists for an improved hook link and combined hook link with paddle assembly as, for example, used on barn or gutter cleaners.